Could someone tell me if this is the correct method of connecting a relay to an open collector output of the fire panel?
The fire panel is a FireClass FC510.
The instructions found in the manual are:
OS1…OS8 Programmable, Silenceable, Bypassable (Disabled), Supervised Outputs.
These are normally-open terminals (open-collector) which will close to ground, when the connected event becomes active, and will remain in this state until the generating event has ended (so after a manual reset or a fault restore).
Connect an EOL 27kohm resistor between terminals [OS] and [GND] of these outputs. This will allow the control panel to detect and signal when the outputs are shorted and/or open.
This is the image from the manual: Open collector wiring2 hosted at ImgBB — ImgBB
I would do it like in the following image. However, I’m not sure it’s the right way.
Sorry, i couldn’t attach the images, that’s why i used the URL’s.
Normally when using a supervised open collector output the controlled device is fed +24 from a source on the fire alarm panel.
Example from FC510 manual:
AUX Auxiliary power 24 V (0.5A max) Power supply to
devices that operate at 24 V (powered by the standby
batteries):
Positive (27.6 V) on terminal [24A]
In drawing 2 it looks like you are wanting to use an external power supply. Feeding an external voltage into the panel could damage the panel, void the warranty, or be a code violation.
If you are proposing to use an external power supply, I have some questions.
Is the external power supply agency listed for fire protective use with the FC510? (UL/FM (North America & Others), CE/ATEX (European Union)
Does the external power supply have battery backup?
Is the external power supply supervised for faults by the FC510?
Is this type connection sanctioned by Bentel?
Bentel should be contacted with questions on this type of operation.
The drawing below is my preferred way of wiring this for light loads, such as control relays, etc. However, the FC510 AUX power output is limited to 0.5 amp. This is similar to using Simplex 4100 24 point I/O card outputs.
Bentel does make the BXM24 series of add on power supplies to operate greater loads. However, I can’t find any literature that approves them being used with the FC510 panel, or how to wire them together. That said, a lot of the literature on line is in languages other than English. Maybe Bentel tech support can give you some advice on these units.
